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  • Category: Technology

    Air preheater performance improvement

    Having a problem in air preheater of boiler? Find advice from experts on this page.

    How to improve the efficiency of air preheater?
    We are facing problem of increase in ESP inlet temperature.
    We observed that the flue gas passage was blocked with ash between APH tubes.But we are unable to find the reason for blockage.
    Can you provide suggestions regarding the problem we are facing in our CFBC BOILER 150TPH?
    Awaiting advice?
  • Answers

    2 Answers found.
  • During the process of combustion, sulfur in the fuel is converted to SO2 and depending on the excess air available, part of SO2 is converted to SO3. The SO3 reacts with H2O
    in the preheater due to cooldown of flue gas will result in the formation of H2SO4.
    * Ensure proper operation of steam coils or preheatr bypass damper to keep the preheater above dew point temperature.
    * For steam coils perform periodic inspections for leakages which will increase the water vapor
    * Increase in oxygen rich air will result in rate of acid deposition and corrosion potential.
    * Cleaning of Preheater Periodically.

  • Air pre-heater is a heat transfer equipment. We must ensure to clean the parts of air pre-heater periodically otherwise fouling will cause the degradation in heat transfer process. The reason is fouling makes heat transfer coefficient to lower which ultimately lowers the rate of heat transfer. Second thing ESP should work properly if it is not working, dust and other particles clogged in it and cause serious trouble for plant process. Allow the clean air to pass though the air pre-heater otherwise air itself lowers the efficiency of air pre-heater.

    Dr. Paresh B. Gujarati.
    Mechanical Engineer.
    'I'mprovement always begins with 'I'.

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